Since firearms were developed, there have been many methods and devices developed for modifying a firearm and adapting such weapons to multiple use variations. One such variation is a shortening mechanism for a long gun, either rifle or shot gun, allowing it to be held on target easily and increase maneuverability and storage capabilities of the weapon. These devices, commonly called “bull-pups” typically involve installing a mechanism with a secondary trigger mounted so that the trigger is in front of the action of the weapon and mechanically linking the secondary and primary triggers. The weapon's stock is then removed and replaced, usually with a component of the new firing mechanism. The resulting weapon is commonly found to be better balanced than the original, unmodified weapon and is, therefore, much easier to handle. However, there are a number of disadvantages with the modules in the prior art. They tend to require extensive modification to the weapon to support the bull-pup module on the weapon and restrict the option of disassembling the weapon as the modules also tend to block the disassembly pivot point of the base long gun. They also have to be exact in their linkage of the two triggers. Any linkage adjustment tends to be difficult or impossible. Positioning of the linkage on the primary trigger must also be exact, as the linkage merely pushes the trigger and misplacement and extra “play” in the linkage can lead to poor trigger capabilities or misfire.
While the prior art inventions accomplish their individual objectives, they do not describe a rail mounted trigger mechanism; nor do they feature a direct, in-line hinged linkage between the secondary and primary triggers allowing for field disassembly of the weapon without removing the module. Neither do they describe an easily adjusted mechanism to eliminate play between the triggers; nor do they disclose a cam and roller mechanism to improve interplay between the secondary and primary triggers. In this respect, the trigger mechanism according to the present invention departs substantially from the usual designs in the prior art. In doing so, this invention provides a lower profile, rail mounted forward trigger module. Further, the cheek rest is also easily mounted to the long gun by clamping to long guns receiver dovetail rails (including 1913 mil spec. rails, also known as Picatinny rails, or Weaver rails).